1. Field of the Invention
The present invention relates to an image measuring method, image measuring system and image measuring program, having a non-stop measurement mode for image measurement, in which an imaging means moves relative to a measurement target supported on a measurement stage and captures instantaneous image information at designated measurement positions without making a stop.
2. Description of the Related Art
A conventional CNC image measuring machine comprises a measurement stage, which is moved relative to an imaging means such as a CCD camera and stopped at a measurement position as shown in FIG. 8. Then, the amount of illuminating light is adjusted to acquire image information about a measurement target. To the acquired image information, image processing such as setting of a measuring tool and edge detection is applied, thereby executing a measurement at one measurement position. This measurement is repeated as Measurement 1, Measurement 2, . . . and so on for all measurement positions to achieve measurements at required positions (hereinafter, such the measurement mode is referred to as a “standard measurement mode”).
In contrast, for the purpose of improving the throughput of measurement, a measurement may be performed without making a stop of the measurement stage relative to the imaging means even at a measurement position in a measurement mode (hereinafter, such the measurement mode is referred to as a “non-stop measurement mode”). An image measuring machine having such the non-stop measurement mode has been proposed (see JP-A 2004-535587, paragraphs 0005-0006, FIG. 2). This image measuring machine irradiates the measurement target with strobe illumination, as shown in FIG. 9, without making a stop of the measurement stage at measurement positions. Alternatively, it captures instantaneous image information imaged using a shuttered CCD camera, for image measurement. In the image measuring machine, the CCD camera is roughly positioned in a measurement region at high speeds and then decelerated to capture images within a predetermined constant speed region.
The above-described conventional image measuring machine has no problem if multiple positions to be measured are arranged in a straight line. In contrast, if the multiple positions are not arrayed in a straight line, on measurement in a non-stop measurement mode, a measurement position may appear at a folded point on a movement path of the imaging means. Therefore, a movement mechanism is overloaded and a problem may arise associated with a blown protective fuse depending on the case. In addition, the movement mechanism may cause vibrations and worsen the measurement accuracy as a problem.